This invention relates to the art of liquid dispensing and, more particularly, to a method and apparatus for filling a container with a predetermined volume of liquid.
This invention has particular utility to automatic dishwashers. It is conventional to fill an appliance of this type by opening up an inlet valve in the water line for a preset time interval. However, this technique possesses the disadvantage that the amount of water entering the dishwasher during this preset time interval is dependent upon the inlet water pressure and, accordingly, the amount of water actually entering the dishwasher is not predictable with any degree of certainty. Alternatively, a water level sensor could be provided and the inlet valve would then be opened until the water level sensor is triggered. However, during the operation of an automatic dishwasher there may be a number of fill cycles, each of which may require a different amount of water. Thus, several level sensors may be required, adding to the expense of the dishwasher. Additionally, it would be desirable to allow the user to select a water level dependent upon the load placed in the dishwasher, e.g., light, normal, or heavy loads. This would also require a number of water level sensors or else be subject to the vagaries of water pressure.
It is therefore an object of this invention to provide an economical means for filling a dishwasher with a predetermined volume of water which is not dependent upon water pressure or a large number of water level sensors for predictable results.